Effects Of Salt Water On Plant Cells.

Extracts from this document...

Introduction

Science Course Work Effects Of Salt Water On Plant Cells Plan I plan to investigate the effect of a salt -water concentration will have on a plant cell. I am going to use potatoes to test if it has any effect by investigating if their size changes after being in the concentration for a period of time. The amount of salt in the concentration is one variable that could affect the experiment but there are others that I must keep the same to ensure accurate results. I must try to keep the temperature as level as possible as a higher temperature will speed up the reaction. I am going to perform each experiment twice and then find an average change. This is to make the experiments results more reliable. The process I am investigating is called osmosis. The definition of osmosis is the diffusion of water through a semi-permeable membrane from a high water concentration to another. Prediction I predict that if there is a low concentration of salt in the water there will be more diffusion and the cells will get bigger. ...read more.

Middle

6. Salt solutions will be needed to test the potato chips Method To conduct the experiment I will bore 10 separate chips from a potato and then cut them to 25mm in length using a vernier calliper to ensure accuracy. I will then add 5 different salt-water solutions ranging from 0 percent salt to 2 percent salt rising in half a percent of salt each time to the ten test tubes. I will then place the 10 potato chips into the test tubes recording their lengths first. I will then leave them for approximately three hours. After that I will remove the chips and measure them to compare with the results before. Results Once the experiment has been conducted I have collected the results and put the data and the data from calculations into a series of tables. Experiment One Percentage of Salt in Concentration Length before the Start of Experiment (mm) Length After Experiment (mm) 0 25 28.2 0.5 23.5 26.2 1 23.3 23.5 1.5 24.6 22 2 25 20.5 Experiment Two Percentage of Salt in Concentration Length before the Start of Experiment (mm) ...read more.

Conclusion

It shows that the less concentration of salt the more the plant cell enlarges. This is because the high water concentration is causes some of the molecules to pass through the membrane into the plant cell in an attempt to even out the levels of water. This then causes the cell to swell. The opposite happens if there is a low concentration of water and this causes the cell to shrink. Evaluation The results that I have collected are reliable because I conducted the experiment twice in order to find an average but the results collected could have been much fairer. They could have been better if I had conducted each different experiment a number of times that way I would have received a much fairer average that could have meant that extreme results would have had less of an effect. I could have also had a wider range of salt concentrations rather than just the five I tested. The time the experiment was left for may also have had an effect on the results. The longer the time would give longer time for the diffusion to take place. ...read more.

Related GCSE Green Plants as Organisms essays

Another improvement that could have been done to improve my results would have been to measure the diameter change of the potato, which in turn would have helped to find out the volume, before and after the experiment, of the potatoes, which would also help to explain the results obtained.

I know this because in my preliminary work I placed a potato chip in 100% water and it expanded and became turgid e.g. the chip before the experiment weighed:4.34 grams and the length before the experiment was 5.6 centimetres. The chip after the experiment weighed:4.25 grams and the length after the experiment was5.8centimetres.

fortified orange juice or milk are principally breakfast items, while water is consumed all day, whether it be on the go, at work or in class. Price Prices vary from one industry to another. Bottled water varies from product to product.

Measure out 200 ml of distilled water and then add 800 ml of table salt, which will create 80 % salt solution. 2) Measure out 200 ml of distilled water and now only add 120 ml of salt, this will create 60 % salt solution.

Ammonia is toxic and may lead to a lower biodiversty in the water stream near the sewage. Hence a nitrate indicator will be used to check for the presence of nitrates in the fresh water stream and support my hypothesis.

Therefore, by piercing very small holes in this barrier, just big enough for the water molecules to travel through, only the water could diffuse to the other corner, whilst the big sugar molecules would remain in their corner. Research in physics books found that that molecules or particles that cannot pass through these tiny holes in the barrier are colloidal.